Trustee Irving Picard has claimed the family members who worked at Madoff's firm should have known about his epic fraud. He says they also profited from the scheme and should return the money to burned investors.

Lawyers for the brother, Peter Madoff, and sons Mark and Andrew argued in court papers that they were in the dark about a massive Ponzi scheme that spanned decades.

The papers were filed late Monday in federal bankruptcy court in Manhattan. The trustee declined comment on Tuesday.